The 2-L1-A monoclonal antibody specifically binds to the human CC chemokine receptor CCR7, also known as CD197, on the cell surface. CCR7 (previously known as BLR2, EBI1 and CMKBR7) is a seven-transmembrane, G-protein-coupled receptor specific for two CC chemokines: CCL19 (also known as MIP-3β, Exodus-3, and ELC) and CCL21 (also known as 6Ckine, Exodus-2 SLC, TCA4, and SCYA21). CCR7 mRNA is expressed mainly in lymphoid tissues including the spleen, lymph nodes and tonsil, in bone marrow, and on peripheral T and B lymphocytes, cord blood CD34-positive cells, and mature dendritic cells. In response to its cognate chemokines, CCR7 (CD197) mediates homing of leucocytes to secondary lymphoid tissues. Differential CCR7 (CD197) expression can be used to distinguish naive, central memory, and effector memory T cell subsets. The human CCR7 gene, unlike other CC chemokine receptor genes, has been mapped to chromosome 17 (region 17q12). Because the extracellular region of CCR2 (CD192) has significant sequence homology with CCR7 (CD197), BD Biosciences has confirmed that mAb 2-L1-A does not cross-react with CCR2 on the surface of transfected cells.
The antibody was conjugated to BD Horizon™ BUV661 which is part of the BD Horizon Brilliant™ Ultraviolet family of dyes. This dye is a tandem fluorochrome of BD Horizon BUV395 with an Ex Max of 348-nm and an acceptor dye with an Em Max at 661-nm. BD Horizon Brilliant BUV661 can be excited by the ultraviolet laser (355 nm) and detected with a 670/25 filter and a 630 nm LP. Due to cross laser excitation of this dye, there may be significant spillover into channels detecting APC-like emissions (eg, 670/25-nm filter).
Due to spectral differences between labeled cells and beads, using BD™ CompBeads can result in incorrect spillover values when used with BD Horizon BUV661 reagents. Therefore, the use of BD CompBeads or BD CompBeads Plus to determine spillover values for these reagents is not recommended. Different BUV661 reagents (eg, CD4 vs. CD45) can have slightly different fluorescence spillover therefore, it may also be necessary to use clone-specific compensation controls when using these reagents.